Plastic bobbin



Sept. 11, 1956 E. C. SCANLON PLASTIC BOBBIN Filed June 4, 1953 INVENTOR. EDWARD C. SCANLON BY M @M arm;

ATTO R N EY United States Patent PLASTIC BOBBIN Edward C. Scanlon, West Barrington, R. I.

Application June 4, 1953, Serial No. 359,477

1 Claim. (Cl. 242'119) This invention relates to improvements in bobbin construction and more particularly to plastic bobbins upon which yarn is wound under high tension.

A primary problem encountered in the use of a bobbin fabricated completely from plastic is the elongation, stretching or distortion of the bobbin barrel both lengthwise, so that the bobbin flanges increase in length, and in cross section or transverse of the length where constriction takes place. The result of this distortion is that the yarn layers, especially the end convolutions, shift position in relation to each other, so that the uniform tension takeoff of the yarn is lost, rendering the wholly plastic bobbin useless.

In addition, a bobbin used in an automatic machine which has a variation in the distance between spool heads, causes nuisance adjustments to be made on the machine to compensate for the variation. If those adjustments are not made the winding of the yarn on the bobbin lacks uniformity rendering the bobbin useless.

The plastic bobbin has many advantages over the wooden bobbin which wear and wobble on the spindle thereby affecting the tension of the yarn as it is drawn off the bobbin. Humidity affects the dimensional stability of a wooden bobbin or spool. It is very costly to make a wooden bobbin accurately. A plastic molded spool is unaffected by humidity and can be made more accurately and cheaply than a wooden bobbin. But the shrinkage of the plastic bobbin cannot be accurately compensated for because of the many variations involved such as temperature, pressure, mixture variations etc.

The primary object of this invention is to retain all the advantages of the plastic bobbin while overcoming all the disadvantages of the plastic bobbin. This result is accomplished by providing a metal sleeve with means for anchoring plastic spool heads on the end of the metal sleeve. This construction minimizes the shrinkage between the spool heads to a degree of negligibility.

The metal sleeve may be provided with a locating aperture preferably midway of its length. The metal sleeve is positioned in a plastic mold. The plasticised material is then molded as a core for the metal sleeve and as spool ends, sometimes termed spool heads.

Another object of the present invention is to provide an improved method of fabricating a bobbin, pirn, spool or reel.

Other objects of the present invention will become apparent in part and be pointed out in part in the following specification and claim.

In the accompanying drawings wherein like reference characters refer to like parts:

Figure 1 is a perspective view of the new and improved plastic bobbin.

Figure 2 is a horizontal sectional view taken along line 2-2 of Figure 1.

2,762,580 Patented Sept. 11, 1956 Figure 3 is a perspective view, partly in section, of the metal core as it is inserted in the plastic molding machine.

Figure 4 is a fragmentary sectional view showing a modified form of anchoring to that shown in Figure 2.

Referring to the drawings wherein reference character 10 generally indicates the new plastic bobbin provided with a metal sleeve 11 having flared or bell mouthed ends 16, 17, a plastic core or bearing 12, preferably nylon plastic, and spool heads 13, 14 formed integral with hearing 12. A locating aperture 15 is provided in metal sleeve 11 mid-Way of its length.

The metal sleeve 11 is placed in a mold with aperture 15 placed over a locating pin in the mold. The liquid plastic material enters the mold at the left side and flows toward the right side between the mold core and the inside diameter of sleeve 11. Spool head 14 is formed completely. As the liquid plastic backs up, a bearing 12 is formed and finally spool head 13 is completed. The flared ends 16, 17 form an anchorage for the spool heads 13, 14 respectively.

Thus a new article of manufacture is produced having a nylon bearing, plastic spool heads and a metal core which prevents distortion and displacement of the spool heads.

The shrinkage of the plastic is controlled by the metal sleeve.

Figure 4 represents a modified form of anchorage for the spool ends. In place of flared or bell mouth ends 16, 17, a serrated end 20 is provided on metal sleeve 11. Thus the spool head 13A can be molded and anchored to metal sleeve 11. In addition bearing 12 need not run the full length of metal sleeve 11 as shown in Figure 2. It may be foreshortened as shown in Figure 4 by reference character 12A. In that event the spool heads would be molded from both sides of a mold or with one spool head being molded to the metal sleeve, at one time.

Having shown and described a preferred embodiment of the present invention, by way of example, but realizing that structural changes could be made and other examples given without departing from either the spirit or scope of this invention, what I claim is:

A bobbin consisting of a metal sleeve, nylon molded as a core in said metal sleeve and formed into spool heads on opposite ends of said metal sleeve, an axial passageway formed in said core to provide a bearing surface of nylon and means on opposite ends of said metal sleeve to anchor said metal sleeve to said spool heads to provide resistance to distortion of one spool head in relation to the other spool head through said metal sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 585,199 Foster June 29, 1897 611,343 Tilden Sept. 27, 1898 949,641 Anderson Feb. 15, 1910 1,860,020 Dunlop May 24, 1932 2,156,632 Kurman May 2, 1939 2,344,132 Coxe Mar. 14, 1944 2,378,901 Amrhein et a1. June 26, 1945 2,431,393 Franklin Nov. 25, 1947 2,448,242 Wilson Aug. 31, 1948 2,651,476 Morin Sept. 8, 1953 FOREIGN PATENTS 257,807 Great Britain Sept. 9, 1926 630,039 Great Britain Oct. 4, 1949 

